PRESERVATIVES In a formula of cream (O/W type) preserved
with 2% A-Silkne and 0.4% glyceryl caprylate, from day 14, bacteria and yeast were not detectable. From day 7 to day 28, mould was gradually decreased. In a formula of shampoo solution preserved with 2% A-Silkne and 0.4% glyceryl caprylate, from day 7, bacteria and yeast were not detectable. From day 7 to day 28, mould was gradually
decreased (Table 2). This suggests that using a 2% A-Silkne with 0.4% glyceryl caprylate shows an excellent preservative effect on various personal care products. This revealed that a formulation A-Silkne with a natural alternative preservative was effective against all microbe containing fungi. This also demonstrated that A-Silkne could be applied to the creation of new preservative-free system for use in the personal care product industry.
Multifunctional benefits – potential of anti-acne agents Acne is a chronic inflammatory disease outbreak in the sebaceous glands within the hair follicle. The proliferation of Cutibacterium acnes (formerly known as Propionibacterium acnes) causes monocytes to stimulate the secretion of inflammatory cytokines. C. acnes hydrolyses neutral lipids into free fatty acids, which promotes oxidative stress, inflammatory reaction, and tissue distruction. C. acnes also interacts with various
components of the immune system. In addition, the aerobic bacteria Staphylococcus aureus proliferates in acne lesions and causes inflammatory skin diseases. Usually, salicylic acid and Centella asiatica extract including madecassoside are used to treat C. acnes. Salicylic acid and Centella asiatica extract can also regulate the proliferation of C. acnes, but they can cause several side effects including dry skin.6
Therefore, the antibacterial activity of salicylic acid and Centella asiatica extract, commonly used ingredients for acne treatment,
7 6 5 4 3 2 1
0 Day 0
Sample conc. (%, w/w)
Day 1 Day 2 Day 3 Day 7 Day 14 Day 21 Day 28
THE NUMBER OF VIABLE
C.ACNES IN OIL BALM LOG REDUCTION (CFU/g) Day 0
A-Silkne Conc. (%, w/w)
Without A-Silkne 1%
2% 3%
5.5 5.9 6.1
0 0 0
0 0 0
0 0 0
INHIBITION ZONE SIZE (MM)
Sample conc. (%, w/w)
2% 1%
0.8% 0.6% 0.5% 0.2%
A-Silkne 32
22 18 10 - -
Centella
asiatica extract - - - - - -
INHIBITION ZONE SIZE (MM)
Sample conc. (%, w/w)
0.5% 0.2% 0.1%
0.05%
0.025% 0.0125%
Salicylic acid -
- - - - -
-: No antimicrobial activity Figure 2: Antimicrobial analysis of A-Silkne against C. acnes
as compared with A-Silkne. To evaluate the anti-microbial activity of C. acnes (C. acnes ATCC 6919), a well diffusion assay was performed. The degree of anti-microbial activity was shown by measuring the diameter of the inhibition zone formed on the plate (Figure 2). In this study, the concentrations of salicylic
acid, Centella asiatica extract, and A-Silkne required to inhibit cell growth of C. acnes were >0.5%, >2%, and 0.6%, respectively. Salicylic acid, which is generally used less than 0.5% due to skin dryness and irritation as an ingredient in personal care products for acne treatment, showed no antibacterial effect at 0.5% concentration. In addition, the antibacterial activity of
Centella asiatica extract was not confirmed against C. acnes. On the other hand, A-Silkne was inhibited the cell growth of C. acnes at
1% ■ 2% ■ 3% ■ Without A-Silkne ■
0.6% concentration. In this study, A-Silkne was able to effectively inhibit C. acnes at a low concentration without causing side effects such as skin dryness or skin irritation. We evaluated the growth inhibitory effect
of A-Silkne on C. acnes in oil balm (Figure 3). For analysis, C. acnes was contaminated with more than 106
CFU/g, and viable C. acnes
was accumulated on days 1, 2, 3, 7, 14, 21, and 28 (Figure 2). As a result, C. acne, which was contaminated in the oil balm, was inhibited by 99.999% after two days. We showed that A-Silkne has excellent
antibacterial activity against C. acnes as well as a powerful protect ability against contaminated C. acnes. According to analysis results, it is expected that effective acne care products can be developed by applying A-Silkne to the products.
(inoculation) Day 1 Day 2 Day 3 Day 7 Day 14 Day 21 Day 28 6.5 6.5 6.5 6.5
0 0 0
6.4 6.0 6.1 6.0 5.8 Figure 3: Analysis of growth inhibitory effect of A-Silkne on C. acnes in oil balm
www.personalcaremagazine.com
0 0 0
5.5
0 0 0
4.9
Multifunctional benefits – potential of alternative silicone oils Silicone oil is one of the most widely used ingredients in personal care products. Silicone oils, such as dimethicone, offer excellent spreading properties and give end-use products a soft, pleasant and non-sticky after-feel. Silicones have exceptional physicochemical and sensory properties but their high chemical stability results in very low biodegradability. Consumers are becoming increasingly sensitive to environmental issues and demand more environmentally friendly personal care products. This recognition strongly encourages the personal care products industries to develop plant derived biodegradable alternatives to silicone oils.7 We conducted a blind sensory test to
compare the spreadability, absorption, moisturising, film formation, and feeling of A-Silkne and silicone oil (Figure 4). As a result, spreadability, absorption, moisturizing and film formation were improved compared to placebo oil balm. In addition, a similar level of feeling after
July 2023 PERSONAL CARE Well size: 6mm N.C. : DMSO
27
The number of viablw C. acnes in oil balm Log (CFU/g)
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92
